Diurnal and semidiurnal tide-induced lateral movement of Ronne Ice Shelf, Antarctica

• Published in: Geophysical Research Letters
• Main Authors: Makinson, K, King, MA, Nicholls, KW, Gudmundsson, GH
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley-Blackwell Publishing 2012
• Subjects: Earth Sciences; Geophysics; Geodesy; Ronne Ice Shelf; Tilting; Antarc*; Antarctica; Ice Sheet; Ice Shelf; Ice Shelves
• Online Access: https://doi.org/10.1029/2012GL051636; http://ecite.utas.edu.au/89656

Recent GPS observations from a spatially extensive networkacross Ronne Ice Shelf show significant daily ice flowvariations. At all sites, the almost-synchronous horizontaldisplacements occur at diurnal and semidiurnal tidal periods.During spring tides, displacements, velocities and strains nearthe ice front have superimposed oscillations that are +-300%of their mean values and occur over a six-hour period, resultingin regular ice shelf flow reversals. Close to ice streamgrounding lines, however, the horizontal diurnal and semidiurnalsignals decay and almost vanish. From our analysis,we conclude that ice shelves respond primarily elasticallyto tidal tilting, thus accounting for the observed diurnal andsemidiurnal flow variations, and their amplification towardthe ice shelf front. Our findings suggest that detailed modelingof these data could provide improved ice shelf and icestream models for correctly simulating ice shelf flow andpredicting future ice sheet evolution.